Printers generally include a print controller that receives raw print data (e.g., Page Description Language (PDL) data), and a print engine. The print controller rasterizes the print job into bitmap data, and the print engine utilizes the bitmap data to mark a printable media, such as paper. Rasterizing raw print data is a time consuming and a computationally intensive process. As such, a rasterizer may not be able to generate raster data fast enough in real time for the print engine during high speed printing. Therefore, modern printing systems may also include one or more hard disk drives, flash drives, or other types of non-volatile storage systems to store bitmap data. Disk(s) or a partition of disk(s) that are used to store bitmap data may also be referred to as a rip spool.
Prior to the print engine marking the media, print data for the job (e.g., PDL data) is rasterized and written to the rip spool. When generating raster data for a job, a rasterizer not only considers the PDL data in the print job, but also the size, type, weight, finish, and other properties of the media that the job is ultimately printed on. This occurs because a number of factors may affect how the same bitmap data “looks” after being printed onto different media. For example, printing the same bitmap data on a glossy finished paper may look different than printing the bitmap data on a plain finished paper. In order to solve this problem, rasterizers analyze various properties of the target media when generating bitmap data in order to tailor the bitmap data to the media. Tailoring the bitmap data to the media may include variations in pel (pixel) size and shape, colorant density, etc. Therefore, a rasterizer uses information about the properties of the target media in order to accurately generate raster data for a job.
In some cases, print jobs may not accurately specify the properties of the target media in sufficient detail to allow the rasterizer to generate the correct bitmap data for the media. For example, a print job may simply reference a printing tray that holds media for the job, such as “tray 1”, or “letter”. In order to rasterize this job correctly, the rasterizer attempts to identify the characteristics of the media currently loaded in tray 1, or in letter trays at the printer in order to determine the characteristics of the media. The rasterizer then uses the characteristics to tailor the bitmap data for the target media. Problems arise, however, when print jobs are ripped and spooled with some delay before being printed. In this case, the media loaded in the print tray when a job is ripped may be different than the desired media for the job. Also, the media loaded in the print tray may change between the time when the job is ripped and when the job is printed. It thus remains a problem to ensure that raster data for a job is generated correctly that is independent of the media currently loaded at the printer.